Materials Data on LiAl(H2N)4 by Materials Project

Abstract

LiAl(NH2)4 crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of eight hydrogen molecules and one LiAl(NH)4 sheet oriented in the (1, 0, 0) direction. In the LiAl(NH)4 sheet, Li1+ is bonded in a distorted tetrahedral geometry to four N3- atoms. There are a spread of Li–N bond distances ranging from 2.01–2.12 Å. Al3+ is bonded in a 4-coordinate geometry to four N3- atoms. There are a spread of Al–N bond distances ranging from 1.86–1.89 Å. There are four inequivalent N3- sites. In the first N3- site, N3- is bonded to one Li1+, one Al3+, and two H1+ atoms to form distorted corner-sharing NLiAlH2 tetrahedra. There is one shorter (1.02 Å) and one longer (1.03 Å) N–H bond length. In the second N3- site, N3- is bonded in a 3-coordinate geometry to one Li1+, one Al3+, and one N3- atom. The N–N bond length is 1.28 Å. In the third N3- site, N3- is bonded in a 3-coordinate geometry to one Li1+, one Al3+, and one N3- atom. In the fourth N3- site, N3- is bonded to one Li1+, one Al3+, and two H1+ atoms to form distorted corner-sharing NLiAlH2 tetrahedra. Both N–H bond lengths are 1.02 Å. There are four inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom.